Shelf



FIG. 1 is a front perspective view of a shelf according to a first embodiment of the new design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a left side view thereof, the right side view being a mirror image of the left side view;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof;

FIG. 8 is a front perspective view of a shelf according to a second embodiment of the new design;

FIG. 9 is a rear perspective view thereof;

FIG. 10 is a front view thereof;

FIG. 11 is a rear view thereof;

FIG. 12 is a left side view thereof, the right side view being a mirror image of the left side view;

FIG. 13 is a top view thereof; and,

FIG. 14 is a bottom view thereof.

The broken lines illustrate portions of the shelf that form no part of the claimed design. 

CLAIM The ornamental design for a shelf, as shown and described. 